Cognitive Impairment Related to Atrial Fibrillation Prevention Trial

Randomized Clinical Trial for the Prevention of Cognitive Impairment in Atrial Fibrillation Patients Treated With Dabigatran or Warfarin

Cognitive and functional decline observed in atrial fibrillation (AF) patients are related to thrombotic and/or cardioembolic events. Use of warfarin for the prevention of stroke in AF patients, despite effective, remains beyond desired levels because of interactions with food and fluctuations in blood levels. Because of a more stable anticoagulation state, Dabigatran may offer better protection against thrombotic phenomenon and, consequently, mitigate the process of cognitive and functional compromise.

This will be a prospective parallel study including two hundred atrial fibrillation patients > 65 years old and scoring CHADS2VASc > 1. Patients will be randomized to receive Warfarin (INR between 2 and 3) or Dabigatran (150 mg twice daily) for two years. After one year and at the end of the study, individuals will be evaluated regarding cognitive endpoints following the National Institute of Neurological Disorders and Stroke-Canadian Stroke Network Vascular Cognitive Impairment Harmonization Standards (Hachinski et al. Stroke 2006;37:2220-2241). The investigators will use the 60 minutes evaluation protocol complemented by the Montreal Cognitive Assessment (MoCA).

Inclusion Criteria:

• Atrial fibrillation
• CHA2DS2-VASc Score for Atrial Fibrillation Stroke Risk (CHADS2VASc) greater than 1

Exclusion Criteria:

• Heart valve disease
• Previous Stroke or Transient ischemic attack
• Cognitive impairment or any severe neurological disorder
• Major surgery in the last 30 days
• Planned elective surgery in the next three months
• Intracranial, ocular, spinal, retroperitoneal, or articular bleeding without trauma.
• Gastrointestinal bleeding in the last 12 months
• Symptomatic gastric ulcer
• Hemorrhagic disease
• Use of thrombolytics
• Uncontrolled hypertension
• Active cancer
• Contraindication for Warfarin use
• Reversible causes of atrial fibrillation
• Creatinine clearance < 30 ml/min
• Active endocarditis
• Active hepatitis
• Severe anemia
• Left ventricle ejection fraction < 35%